types/struct.c

   1 /*
   2  * struct.c
   3  *
   4  * BabelTrace - Structure Type Converter
   5  *
   6  * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  */
  18
  19 #include <babeltrace/compiler.h>
  20 #include <babeltrace/format.h>
  21
  22 #ifndef max
  23 #define max(a, b)       ((a) < (b) ? (b) : (a))
  24 #endif
  25
  26 void struct_copy(struct stream_pos *dest, const struct format *fdest,
  27                  struct stream_pos *src, const struct format *fsrc,
  28                  const struct type_class *type_class)
  29 {
  30         struct type_class_struct *struct_class =
  31                 container_of(type_class, struct type_class_struct, p);
  32         unsigned int i;
  33
  34         fsrc->struct_begin(src, struct_class);
  35         fdest->struct_begin(dest, struct_class);
  36
  37         for (i = 0; i < struct_class->fields->len; i++) {
  38                 struct field *field = &g_array_index(struct_class->fields,
  39                                                      struct field, i);
  40                 struct type_class *field_class = field->type_class;
  41
  42                 field_class->copy(dest, fdest, src, fsrc, field_class);
  43
  44         }
  45         fsrc->struct_end(src, struct_class);
  46         fdest->struct_end(dest, struct_class);
  47 }
  48
  49 void struct_type_free(struct type_class_struct *struct_class)
  50 {
  51         unsigned int i;
  52
  53         g_hash_table_destroy(struct_class->fields_by_name);
  54
  55         for (i = 0; i < struct_class->fields->len; i++) {
  56                 struct field *field = &g_array_index(struct_class->fields,
  57                                                      struct field, i);
  58                 type_unref(field->type_class);
  59         }
  60         g_array_free(struct_class->fields, true);
  61         g_free(struct_class);
  62 }
  63
  64 static void _struct_type_free(struct type_class *type_class)
  65 {
  66         struct type_class_struct *struct_class =
  67                 container_of(type_class, struct type_class_struct, p);
  68         struct_type_free(struct_class);
  69 }
  70
  71 struct type_class_struct *struct_type_new(const char *name)
  72 {
  73         struct type_class_struct *struct_class;
  74         struct type_class *type_class;
  75         int ret;
  76
  77         struct_class = g_new(struct type_class_struct, 1);
  78         type_class = &struct_class->p;
  79
  80         struct_class->fields_by_name = g_hash_table_new(g_direct_hash,
  81                                                         g_direct_equal);
  82         struct_class->fields = g_array_sized_new(false, false,
  83                                                  sizeof(struct field),
  84                                                  DEFAULT_NR_STRUCT_FIELDS);
  85         type_class->name = g_quark_from_string(name);
  86         type_class->alignment = 1;
  87         type_class->copy = struct_copy;
  88         type_class->free = _struct_type_free;
  89         type_class->ref = 1;
  90
  91         if (type_class->name) {
  92                 ret = register_type(type_class);
  93                 if (ret)
  94                         goto error_register;
  95         }
  96         return struct_class;
  97
  98 error_register:
  99         g_free(struct_class);
 100         return NULL;
 101 }
 102
 103 void struct_type_add_field(struct type_class_struct *struct_class,
 104                            const char *field_name,
 105                            struct type_class *type_class)
 106 {
 107         struct field *field;
 108         unsigned long index;
 109
 110         g_array_set_size(struct_class->fields, struct_class->fields->len + 1);
 111         index = struct_class->fields->len - 1;  /* last field (new) */
 112         field = &g_array_index(struct_class->fields, struct field, index);
 113         field->name = g_quark_from_string(field_name);
 114         type_ref(type_class);
 115         field->type_class = type_class;
 116         /* Keep index in hash rather than pointer, because array can relocate */
 117         g_hash_table_insert(struct_class->fields_by_name,
 118                             (gpointer) (unsigned long) field->name,
 119                             (gpointer) index);
 120         /*
 121          * Alignment of structure is the max alignment of types contained
 122          * therein.
 123          */
 124         struct_class->p.alignment = max(struct_class->p.alignment,
 125                                         type_class->alignment);
 126 }
 127
 128 unsigned long
 129 struct_type_lookup_field_index(struct type_class_struct *struct_class,
 130                                GQuark field_name)
 131 {
 132         unsigned long index;
 133
 134         index = (unsigned long) g_hash_table_lookup(struct_class->fields_by_name,
 135                                                     (gconstpointer) (unsigned long) field_name);
 136         return index;
 137 }
 138
 139 /*
 140  * field returned only valid as long as the field structure is not appended to.
 141  */
 142 struct field *
 143 struct_type_get_field_from_index(struct type_class_struct *struct_class,
 144                                  unsigned long index)
 145 {
 146         return &g_array_index(struct_class->fields, struct field, index);
 147 }